Acetaldehyde in beer before bottling

[Philmac]

I have an issue with a saison i have brewed (8th July)- it has a sickly apple flavour to it. I have read that it is acetaldehyde.

I still have it in the primary fermenter.
It was mashed at 63 degrees.

The gravity has hit its target-

Target O.G.- 1.065
Actual G- 1.052
Target F.G.- 1.012
Actual F.G- 1.010

The yeast is Wyeast 3724 Belgian Saison yeast.
Is this a common problem and have i done the right thing leaving it in the fermenter?
I have read that i should leave it and hope that it is a metabolite of the process that will be reduced?
Is it possible that it is an infection? I have reviewed my sanitation practices as a caution.
I have a plate cooler- i think i sanitise it adequately but i have read a bit about them. I've struggled to get it working properly anyway!
I think the apple flavour has decreased since the last tasting, but it still certainly undrinkable...!

Thanks

 

[RM-MN]

Warm the beer to the low to middle 70's to help the yeast reduce the acetaldehyde. Give it a few days and then sample it to see if it changed.

 

[Qhrumphf]

Is it like a green apple jolly rancher? Or a ripe red apple? They're different compounds.

 

[Philmac]

Its more a sickly sweet sharp green apple than red- from what i have read it is acetaldehyde and my solution is simply to leave it in the fermenter for an extended time for it to breakdown- that's correct yeah?
It's a bit higher than mid 70s now, but i'll leave it to cool from now. it''s been in there for almost 3 weeks- i'll leave it for another week and see how it goes. It is less strong than it was early on- i thought it was an infection and was worried it was a lost batch!
Cheers!

 

[dmtaylor]

Acetaldehyde is volatile at temperatures above 70 F. Keep it warm, not cool. Yeast might absorb some of it, but you might be better off with bleed & feed with CO2 if you have that capability. Keep it warm and flush with fresh CO2 every couple days for a couple weeks to see if that gets rid of it. I haven't tried this but in theory it *should* work.

 

[Qhrumphf]

I don't usually perceive acetaldehyde as sweet, usually the opposite.

However, sickly sweet plus acetaldehyde could be a sign of stuck fermentation.

 

[brewcat]

Sounds like your yeast pitch rate was low. Did you make a starter? How old was the Wyeast package? Time and higher temps should help.

 

[Philmac]

That weird flavour has not gone away yet- just tried it now and it’s still quite strong- is there anything else that it could be? An infection maybe?...

 

[dmtaylor]

Did you warm it up?

It's possible it could be infected. Have you noticed any unusual pellicle (skin) on top, or particles or stringy material in the beer?

 

[Harry482]

Been there, done that from underpitching. My experience was that while it faded with time, it continued to be a pronounced flavor. I dumped it after punishing myself through a few pints.

 

[rtstrider]

Is it possible that bottling and aging a tad (3 weeks+)may fix this? Only reason I ask is when the fermentation kicks back off due to priming sugar would that be enough to get the yeast moving again? If not I'd leave in the primary and on the yeast cake. You can try re-rousing the yeast for giggles and see if that helps after a week or so.

 

[mongoose33]

When you say you mashed at 63 degrees; celsius, not fahrenheit?

That equates to about 145 degrees fahrenheit, which is very low, IMO. I wouldn't be below about 149 unless your goal was to create a very dry beer.

Now, if you're FERMENTING at 63F degrees, for a Saison that's very low. Wyeast says 70-95 is the temperature range, and you want it to be warm, not cool.

So--we need some clarification on this. At what temp did you ferment the wort? Mash temp?